Mine roof jack



MINE ROOF JACK Filed Sept. 14, 1949 IN VEN TOR.

JQMEJ M. HILL United States Patent MINE ROOF JACK James M. Hill, Morgantown, W. Va, assignor, by mesne assignments, to The Colmol Company, New Lexington, Ohio,.a corporation of Ohio Application September 14, 1949, Serial No. 115,657 l Claim. (Cl.- 243-354) This invention relates generally to structures for supporting roof beams in a mine and more particularly to roof jacks spiked in a vertical wall and carrying the ends of a beam to support the roof of the mine.

In the art of deep mining and particularly in some soft coal mines it is frequently necessary to timber or otherwise support the roof of the mine while the work of removing the coal is carried on. When the coal is completely mined out, coal pillars are progressively removed from the remote sections of the mine toward the entry and the timbering posts are withdrawn as the work proceeds. As much timbering as possible is reclaimed for further use.

Timbering posts may be wood logs or metal jack posts with a broad head and foot. Short plates and wedges are used with both structures although the metal jack posts are generally provided with an adjustable screw. Some jack posts have telescoping members with transverse holes to quickly make large adjustments and the screw provides for small adjustment. These metal jack posts are quite heavy and are very expensive in comparison glllith the wood posts. Every attempt is made to reclaim The difficulty encountered with all timbering posts is that they must be placed on a suitable pillow block or other foundation if the floor of the mine is not solid or good rock foundation. Each post foundation usually requires a pillow block or wedge under its foot which requires a lot of timber. There is also a tendency to use smaller cross timbers and more posts which frequently have to be changed or moved in order to get equipment through the mine.

The principal object of this invention is the provision of a short and relatively inexpensive jack for supporting timbers in a mine. This jack does not require a pillow or wedge block for a foundation or at the top. This jack has an angle member to engage the end of the cross or roof timber and its other end is provided with a pick or spur point that enables the jack to be set in the vertical side wall or coal pillar and hold up the timber. This eliminates the use of any floor footing or head blocks and the mining machinery may pass freely without striking or otherwise destroying the timber. These jacks may be set in the face of a continuous wall and are provided with a cross foot or rung that prevents the jack from driving the spur into the coal when it is set into the face of the coal. If it is desired to set the jacks completely out of sight, a nitch may be cut into the wall and the jack set therein. A rotary chipping head cutting arcuate kerfs in the coal forms a natural shelf above solid coal on which to mount the spur of the jack.

Again, the jack comprising this invention is provided with a turnbuckle for quickly setting the pressure between the timber and the wall before the temporary support is removed. In some instances it is not necessary to use a temporary support as the jacks may be set and the timber held in place by hand until the jacks are expanded to permanently support the timber and the roof thereabove.

In reclaiming the timbers and jacks they may be caught with a chain or hook latch and pulled at the same time the timber is pulled free. The jacks are so small as compared to a timbering post that they are readily pulled free of a fall.

Other objects and advantages appear in the following description and claim.

The accompanying drawings show, for the purpose of exemplification without limiting the invention or the "ice 2 claimv thereto, certain practical embodiments of the. in.-

vention wherem:

Fig. 1 is a view 1n s de, elevation of the timber ack ,comprising 7 this invention;

Fig. 2 is a view in front elevation of the structure shown in Fig. 1; and

Fig. 3. is a view in reduced size illustrating the jacks supporting a beam.

Referring to the drawing, the jack 1 comprises the pick point of spur 2 which is sharpened to dig or drive itself into the coal. This spur is on thebottom of the foot 3. Above. the spur the foot 3V is provided with the. cross member 4 welded in place as indicated at.5.. This cross member may be in the form of a disc or bar and it prevents the spur from being embedded in the coal any deeper than the distance from the cross member 4 and the spur point.

The upper portion of the foot 3 is threaded as llldlcated at 6 to receive the lower nut section 7 of the turnbuckle 8. The upper nut section 9 of the turnbuckle receives the threaded end 10 of the" head 11. As shown, the thread 6 is right hand and the thread 10 is left hand. Thus, rotating the loop 8 of the turnbuckle in a clockwise direction, as viewed from above, will cause the jack to retract and when rotated in the opposite direction will cause the jack to expand.

The head 11 is provided with a timber seat in the form of a transverse angle member 12 which is welded in place as indicated at 13. The angle member 12 has suflicient length to prevent lateral rocking of a beam resting thereon. The angle member 12 is made up of the horizontal flange 14 and the vertical flange 15 disposed at to each other. The upper end of the head bolt 11 is preferably welded to the underside of the horizontal flange 14 and at an angle thereto which determined the pitch of the jack when the flange 14 is horizontal. In some 1nstallations where the beams leave little space for setting the jacks this angle may be materially less than that shown. In other installations it may be desirable to arch the jacks at a greater angle than that shown, which 1s approximately 60".

In setting the jacks, as illustrated in Fig. 3, it is preferable to place the point 2 toward the face or wall and allow the cross arm 4 to be on the outside so that the point will pull the jack into the wall as it sinks deeper into the coal. As shown in Fig. 3, the right jack has its spur in a vertical wall; whereas the left jack is turned and has its spur on the upper kerf of a wall cut by a rotary chipping head which simulates a ledge or alcove.

One particular advantage of a jack of this character resides in the fact that there are no posts extending to the floor of the mine. Since these jacks are spurred into solid coal they need no footing or other type of support. If it is desirable to take another bite on a jack of this type the beam 16 may be braced by a floor post but they are usually wide enough so that two or even three jacks may be set at one end. The outside jacks being employed to hold up the beam while the intermediate jack is reset, or a multiple of these jacks may be used at each end of very heavy timbers.

It has also been found advantageous to utilize the flange 15 as the horizontal flange under the beam and the flange 14 as the vertical flange as shown at the left in Fig. 3. This disposes the jack at approximately from the vertical which in some instances is preferable. This places the jack 60 from the roof and clear of everything. This timber jack is thus quite flexible in its use and the loop of the turnbuckle is always accessible for tightening regardless of which way it is turned.

While, for clarity of explanation, certain preferred embodiments of this invention have been shown and described, it is to be understood that this invention is capable of many modifications, and changes in the construction and arrangement may be made therein and certain parts may be employed without conjoint use of other parts and without departing from the spirit and scope of this invention.

I claim:

A coal mine roof-beam jack consisting of a turnbuckle having a loop with a threaded socket in each end, the

3 threads of said sockets being of opposite hand, a complementary threaded rod for each socket, a bit on the outer end of one rod formed into a point by a single plane that intersects the axis of the rod at an acute angle to produce a directional penetrating chisel point bit, a crossbar materially longer than the width of said rod and secured to one side of said rod above the face of the point to position the crossbar on the opposite side of the rod from the point, said crossbar providing a holding grip and to limit the depth to which said point can penetrate the coal, an angle iron seat having beam supporting faces on flanges disposed at 90 to each other for receiving the end of the mine roof-beam, the outer face of one of said flanges being secured to the outer end of said other threaded rod, said rod being secured with its axis spaced from but closer to the apex of the angle iron than to the outer edge of said flange, the outer face 4 of said one flange adjacent the apex forming an acute angle with the axis of the rod to position the principal component of the transmitted force normal to said one face when the resultant component of the transmitted force is axial of said rod, said angle iron seat being substantially the same length as said cross bar.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 617,163 Jacobs Jan. 3, 1899 634,905 McCauley Oct. 17, 1899 704,403 Thill July 8, 1902 835,835 Schumacher Nov. 13, 1906 2,470,396 Guerette May 17, 1949 

